Panels cut successively from a fabric strip have been used for example as decorative faces on room divider units, of the kind employed to divide an office space into separate work areas. Such panels are required to be mounted such that the weave aligns with the office divider edge. Previously, the fabric strip was led from a roll past a measuring station and cutting station. The measuring station determined when an adequate length of strip had moved to the cutting station to stop the strip at a proper location so that the desired length of panel would be cut from the strip. An additional length of fabric is added to the current cut in order to compensate for misaligned weave. At the cutting station, a carriage supporting a cutter moved transversely across the strip to sever the panel from the strip.
However, the weave of such fabric will typically distort if locally tensioned. It is thus common for the transverse elements (e.g. yarns or threads) TE (FIG. 1) of the fabric to deviate from perpendicularity to the longitudinal elements LE and length direction A of the strip S at the cutting station. Such deviation may be as shown in FIG. 1, in which transverse elements TE are skewed to slope downward and to the right in the drawing. Alternately, such deviation may involve transverse elements skewed in the opposite direction or bowed either convexly or concavely in the plane of the strip. The cutting tool in the prior apparatus would not cut parallel to such deviated transverse elements, but rather would cut perpendicular to the length direction of the strip and hence at an angle to transverse elements of the strip, and thus cut through a number of said transverse elements as it cut across the strip. However, the longitudinal and transverse elements of the finished panel must lie perpendicularly of each other, to present an acceptable appearance. The panel thus produced by such prior cutting technique, by selective tensioning, could have its transverse elements reoriented to substantial perpendicularity to its longitudinal elements, but only by distorting its perimeter shape from rectangular e.g., to a parallelogram shape as in FIG. 2. The prior technique thus made it necessary to cut a panel P' overlong, with waste (e.g. the waste 57 indicated in FIG. 2) that had to be trimmed therefrom to produce the finished rectangular panel of FIG. 3. The prior technique thus disadvantageously wasted fabric (yielding fewer panels per roll of fabric), required additional manufacturing time and effort to align the fabric to the office partition and thus unnecessarily increased the cost of production of fabric covered office partitions and dividers.
Accordingly, the objects and purposes of this invention include provision of a method and apparatus for cutting a series of panels from the end of a fabric strip, which: (1) avoids the above-mentioned disadvantages of the prior technique; (2) visually tracks and cuts along a transverse element (or an elongate transverse gap between adjacent transverse elements) despite deviation of such transverse element or elongate gap from strict perpendicularity to the length direction of the strip; (3) avoids or minimizes cutting of transverse elements; and (4) permits the cut off panel, by appropriate tensioning, to have initial skewing or bowing of transverse elements removed therefrom and to thereby resume the desired finished rectangular shape without trimming waste fabric therefrom.
In general, the objects and purposes of the invention are met by providing a method and apparatus for cutting off selected length panels from an indefinite length strip of fabric with little or no waste, the fabric being comprised of superposed longitudinal and transverse elongate elements, wherein the transverse elements may deviate from strict perpendicularity to the length direction of the strip, e.g., may be skewed or bowed. The strip is supported with its longitudinal elements aligned along a path. Cutter means are actuable for cutting elements of the strip to remove a panel from the strip. Transverse moving means are provided for relatively moving the cutter means and strip in a direction transverse to the length of the strip to cut the full width of the strip and thereby separate a panel therefrom. Longitudinal moving means are provided for relatively moving the cutter means and strip in a direction longitudinal of the strip. Vision guided means are optically responsive to deviations in the direction of at least one of the transverse elements adjacent the cutting means for actuating the longitudinal moving means to relatively move the cutter means and strip to enable the cutter means to cut the strip substantially along a single transverse element and at least substantially avoid cutting of transverse elements, despite skewing or bowing of such transverse elements from perpendicularity with the length direction of the strip.